Controlling the air supply in locomotive furnaces provided with preheaters



March 31. 1925. 1,531,707

F. LJUNGSTROM CONTROLLING THE AIR SUPPLY IN LOGOMOTIVE FURNACES PROVIDED WITH PREHEATERS Filed April 13, 1922 Patented Mar. 31, 1925.

UNITED STATES.

PATENT OFFICE.

) I I FREDRIK Lmnesrnou, or LInINeO-BnEvm, SWEDEN, assronoa 'ro AKTIEBOLAGET mouosrnoms anerumam, OE srooxr'romr, SWEDEN, A oonromrron.

CONTROLLING TEEAIR SUPPLY IN LOCOMOTIVE FURNACES PROVIDED HEATERS;

WITH PRE- Application filed April 13, 1922. Serial No. 552,421.

To all whom it may 00ncem."

Be it known that I, FREDRIK LJUNG- s'rRoM, subject of the King of Sweden, residing at Lidingo-Brevik, Sweden, have mvented certain new and useful Improvements in Controlling the Air,v Supply in Locomotive Furnaces Provided with Preheaters, of which the following is a specification.

To obtain a better economy in the furnaces of locomotives it has been proposed heretofore to preheat the air for combustion by means of the flue gases in am air-preheater provided with a forwardly directed air-intake. An air-preheater placed in such a manner constitutes in itself a catching funnel for the incoming air and provides. for Suitable channels for the passage of the air therethrough, by reason of which only the air-current which is produced in the airpreheater without the aid of fans on account of the velocity of the air through the preheater is suflicient to produce a forced draught with overpressure in the furnace. It bein assumed that the air pressure in front 0 the preheater is great on account of the speed of the locomotive forwards, there will therefore be a comparatively great overpressure in the furnace, and thus feeding of the fire by opening the furnace door while the air is allowed to flow freely into the preheater may cause an air-current out of the furnace through the furnace opening, which air-current may bring fuel or combustion products along with it.

The present invention relates to an arrangement for-controlling the air-supply in locomotive furnaces provided with air-preheaters, and consists of dampers or screens disposed in front of the air-preheater and adapted to be controlled from the drivers cab by means of a controlling device. These dampers or screens are so arranged with respect to the furnace door or doors that of the groups comprising dampers or screens and furnace door or doors only one of the two can be open. The screens or the dampers and the furnace door or doors may then'be so combined with each other that the latter cannot be open or be opened without the screens or the dampers being closed. On the other hand the said combination is preferably so arranged that, if the furnace door or doors are open and the screens or dampers screens, and "Fig. 3 a portion of Fig. l in plan view. I

In Fig. 1, the air-preheater is designated by 1 and is situated in this case below the smoke box 2, said preheater having its airmtake 3 directed forwardly against the air WlllCh, on account of the motion of the train, produces a pressure rearwards, the direction of which relatively to the direction of movement of the train is designated by 4.

The flue gases from the furnace enter the rear space 5 of the smoke box, which is divided in. two parts, andpass in the direction of the arrow around the tubes of the air-preheater and through the front part of the smoke box and the smoke stack out in the Open air. When the locomotive is supposed to move forwards at a great speed, the airpreh'eater catches the air required for the combustion in the furnace through the tubes. At high speeds of the locomotive this quantity of air may exert so great an overpressure in the furnace that firing cannot take place. The air supplied must therefore be throttled in firing, and it has been suggested to effect this in lmown manner, for instance by a damper arrangement in the passage 6. It is believed to be more advantageous, however, to control the air flowing into the air-preheater by means of the hereinbelowdescribed throttling device for the air supplied. Besides, this device may be made in such a manner that, even if the throttling device he closed, a sufficient amount of air is always permitted to enter the furnace through the preheater as preheated air, in order to always keep the fire alive in the furnace.

In Fi screens or dampers disposed in a frame work. This frame work, together with the screens, 18 shown 1n 'Fig. 2 viewed from the front,

1 and 3, this throttling device is indicate at 7 I and consists of rotatable all) the screens in the right portion 8 thereof being thensupposed'to be closed, while the remaining ones are open at 9.

In Fig. 1, it is shown how air may always enter the air-p-reheater by the screen device being placed at a distance 11 in front of the airq irehcater, through which space 11 a free air-passage is always provided, without the air supplied causing too great a pressure'in the furnace. All screens may be opened or closed by a single movement of a handle located in the drivers cab.

The above-mentioned relation between the furnace doors and the screens, namely that only one of the two shall be permitted to be open, may be attained in the simplest way by the same being mechanically connected in such a manner that, on the furnace doors being opened, the screens are closed, and vice versa. For various reasons, it is more advantageous, however, to use locking devices in such a manner that, on the screens being open, the furnace doors are locked in closed position, and, on the furnace doors being open, the screens are locked in their closed position. An embodiment of such a locking device is shown in Fig. 2.

In Fig. 2, the furnace opening is provided with two furnace doors 12 and 13 which are opened by switching the handle 11 over from the position 15 to the position 16, whereby the doors 1.2 and 13 are moved in the direction of the arrows 17 and 18 respectively.

The door 12 is connected at the top with a ruler 19 provided with a circular recess 20, a corresponding segment 21 in a controlling device 22 for the screens engaging in the said recess 20 in the closed position of the screens, thereby preventing the ruler from moving together with the door 12 in the direction of the arrow 17 the doors being thus locked in their closed position. The doors may be opened only on the controlling device 22 having been switched over to the position 23, the screens being then closed, in that the segment 21 is rotated by the said movement out of the circular recess 20 in the ruler 19, thereby permitting the free passage of the ruler. From the controlling device, which at the handle 22 is provided for instance with a sheave 24 controlling devices to open and close the screens and the furnace door may be conceived, without the principle of the invention being thereby departed from.

Claims.

1. In combination, an air pro-heater for locomotive furnaces, movable doors associated with the furnace, damping means for controlling the supply of air to the preheater and door locking means actuated by the damping means and preventing opening ofthe doors while the damping means is in open position, said locking means further acting to prevent the opening of the damping means while the doors are in open position.

2. In combination, an air pre-heater for locomotive furnaces, furnace doors, damping means for controlling the supply of air to the pre-heater, and means for preventing the doors from being opened while the damping means is in open position, the last mentioned means also acting to prevent the damping means from being opened while the furnace doors are in open position.

3. In combination, an air preheater for locomotive furnaces, dampers arranged in font of the air preheater for controlling the supply of air to the latter, said dampers and air preheater having a space therebetween through which space air may flow when the dampers are closed, and'means for controlling said dampers from the locomotive cab.

In testimony whereof I aflix my signature in presence of two witnesses.

FREDR 1K. LJ UNGSTROM.

Witnesses O.- SvENsnN, L. BERes-LINDE. 

